@article{1c5347e6d91c4a0d9614b107efdcf130, title = "Antiparkinsonian effects of a metabotropic glutamate receptor 4 agonist in MPTP-treated marmosets", abstract = "Background: Increased firing across glutamatergic synapses may contribute to both the motor dysfunction and L-DOPA-induced dyskinesia seen in Parkinson’s disease. Given their ability to reduce glutamate release, activation of group III metabotropic glutamate receptors such as metabotropic glutamate receptor 4 may prove effective against both motor dysfunction and dyskinesia in Parkinson’s disease. Objectives: We hypothesised that activation of metabotropic glutamate receptor 4 by an orthosteric agonist ((2S)-2-amino-4-(hydroxy(hydroxy(4-hydroxy-3-methoxy-nitrophenyl)methyl)phosphoryl)butanoic acid, LSP1-2111) would produce antiparkinsonian activity and reduce expression of dyskinesia in a 1-methyl-4-phenyl,1,2,3,6-tetrahydropyridine (MPTP)-treated marmoset model of Parkinson’s disease.Methods: Common marmosets were previously treated with MPTP and pre-primed with L-DOPA for up to 28 days to express dyskinesia. LSP1-2111 (1, 3 or 6 mg/kg s.c.) or vehicle (0.9{\%} saline s.c.) were administered immediately prior to L-DOPA (8 mg/kg + benserazide (10 mg/kg) p.o.) or vehicle (10{\%} sucrose p.o.). Locomotor activity was measured in automated test cages and animals were scored for dyskinesia and disability.Results: As expected, L-DOPA reversed motor disability and induced moderate dyskinesia. By contrast, LSP1-2111 alone significantly reduced the motor disability without any accompanying expression of dyskinesia. When administered in combination with L-DOPA, LSP1-2111 did not significantly reduce the severity of L-DOPA-induced dyskinesia.Conclusions: Systemic administration of LSP1-2111 reduces motor disability without causing dyskinesia in MPTP-treated marmosets, supporting a role for metabotropic glutamate receptor 4 orthosteric agonists as promising monotherapy for PD. Conversely, this study found no evidence to support their use as antidyskinetic agents within the dose range tested.", author = "Lizzie Mann and Michael Jackson and Louise Lincoln and Ria Fisher and Sarah Salvage and Susan Duty", note = "This work was funded by an MRC PhD CASE Studentship joint with Eisai Ltd., awarded to EM under the supervision of Dr Peter Atkinson.", year = "2020", month = "3", day = "5", language = "English", journal = "Journal of parkinsons disease", issn = "1877-7171", }